Which of the following describes a compressive force applied to the Earth's crust that results in an anticline?

A compressive force applied to the Earth’s crust leads to deformation and folding of rock layers due to the intense pressure exerted. When two tectonic plates push toward each other, this compression causes the strata of rock to bend rather than break. An anticline forms when these rock layers arch upwards, creating a peak. The folding occurs because the material is subjected to stresses that alter its shape, resulting in the distinct upward curvature of the rock formation seen in an anticline.

This process contrasts with other phenomena like stretching, which would lead to different types of geological formations. Loss of density pertains more to isostasy or other processes, while wave propagation relates to seismic waves generated by earthquakes, which do not directly explain the formation of structures like anticlines. Thus, folding is the term that best captures the geological process involved in creating an anticline under compressive forces.